Corn heads are agricultural implements configured to be supported on the front of a combine harvester. The corn head is typically arranged as a laterally extending transverse frame on which several row units are fixed. The row units are spaced equidistantly across the leading edge of the corn head frame.
Row units are driven by one or more driveshafts that extend in a transverse direction parallel to the transverse extent of the corn head frame.
In one common arrangement, shown in EP 1,820 387 A1, all of the row units on at least one side of the corn head are driven by a common polygonal driveshaft. that can be 15-20 feet long and pass through 6-8 separate row units.
In order to repair the row units, this driveshaft must be removed. The removal process typically requires a farmer to support the corn head on agricultural harvester, unbolt a cover at the outer end of the corn head, attach a chain to the end of the corn head driveshaft, attach the other end of the chain to a tow vehicle, such as a tractor or truck, and then remove the 15-20 foot long corn head driveshaft by pulling it out of its 6-8 row units with the tow vehicle.
This process takes an extended period of time, and typically two or more people to perform. The replacement process is even more time-consuming, since the long driveshaft must be inserted into the corn head and threaded through the 6-8 row units one at a time.
Another arrangement, shown in EP 0 775 437 B2 is for a forage harvester. There are several gearboxes that drive rotating knives and conveyors. The gearboxes have internal driveshafts that are splined at each end and extend outward from either side of the gearbox. Another arrangement, shown in U.S. Pat. No. 7,640,718 B2 shows several gearboxes for a forage harvester that have short drive shafts extending through the gearboxes and stub axles with universal joints that connect the driveshafts that extend from each gearbox. Another arrangement, shown in DE 103 16 003 A1 shows a parallel drive arrangement for driving row units on corn heads. Another arrangement, shown in U.S. Pat. No. 6,349,258 B1 illustrate a drive arrangement for driving transversely adjustable row units.
What is needed, therefore, is an improved driveshaft arrangement for a corn head that permits individual row units to be removed and replaced more quickly and easily.